Biomass pellets fuels make use of the waste materials into biomass fuels, with the help of biomass pellet machines, process the straw, crop stalks, sawdust, corncob, rice husk and etc. into biomass pellet fuels which can be burned directly through the compression moulding. The way to turn these raw materials into treasure is to require biomass pellets boilers.
At present, China's cities have a large number of coal-fired boilers, most of which are distributed in urban areas and around the city. Due to the burning of low-quality coal with high sulphur content, and because the boiler has no desulfurization device and low operation and other factors, black smoke is emitted. Sulfur pollution has a direct impact on the air quality in and around cities. For this reason, the demand for electricity to cancel urban coal boilers and coal to gas is very high, and many cities have taken action, but because of the shortage of gas sources, electricity prices are high. But the city heat does not reach the area, the result is very little. Replacing coal with clean biomass fuel becomes one of the options in urban boilers. But the structure of most boilers is not suitable at present. Biomass fuel is used, and biomass fuel combustion device solves the burning problem of biomass fuel in boiler. According to the characteristics of biomass fuel volatilization, it synthetically applies various clean combustion technologies, such as reverse burning, coal gasification, suspended combustion and so on, which makes biomass pellet fuel burn completely and solves the essential problem of black smoke emission.
Combustion principle of biomass pellet fuels boiler
The biomass fuel is evenly laid on the upper grate from the feeding port or the upper part, after igniting, the fan is opened, the volatilization in the fuel is analyzed, the flame burns down, and the area formed by the hanging grate in the unburned zone forms a high temperature area quickly. Creating conditions for continuous and stable ignition, hot fuel and unburned particles, smaller than the upper grate gap and burned out of volatile matter, falling down while burning, under the action of a fan and gravity, After falling on a very high temperature suspended grate for a moment, it continued to fall, and finally fell to the lower grate, where the incomplete burning fuel particles continued to burn, and the burned ash particles fell from the lower grate into the ash hopper of the ash plant. When ash deposits to a certain height, open the ash gate and discharge. In the process of fuel falling, the secondary air distribution outlet is supplied with oxygen for suspended combustion. The oxygen supplied by the third air distribution outlet contributes to the combustion of the lower grate, and the completely burned flue gas leads to the convection heating surface through the flue gas outlet. When large particles of smoke pass up through the partition plate, because of their inertia, the dust is thrown into the ash hopper, and the slightly smaller dust is blocked from falling into the ash hopper through the dust removal baffle net. Only some extremely small particles enter the convection heating surface, thus greatly reducing the accumulation of ash on the convective heating surface. The heat transfer effect is improved.
The characteristics of pellets fuels made by biomass pellet machines
- A high temperature zone can be formed rapidly, and the laminated combustion, gasification combustion and suspended combustion state can be maintained stably. The flue gas has a long residence time in the high temperature furnace, after many times of oxygen distribution, the combustion is sufficient, and the fuel utilization ratio is high, which can fundamentally solve the problem of black smoke emission.
- The boiler with its matching, the smoke and dust emission original concentration is low, may not use the chimney.
- The fuel combustion is continuous, the working condition is stable, and it is not affected by the addition of fuel and the fire, so the power can be guaranteed.
- High degree of automation, low labor intensity, simple operation, convenient, no complicated operation procedures.
- The fuel has wide applicability and no slagging, which solves the problem of easy slagging of biomass fuel.